1. Field of the Invention
This invention relates to the art of surgical trocars and more particularly concerns an improved trocar assembly having plural cannulas for draining fluid from a body part, for repeatedly washing the body part and for draining the wash fluid after each wash.
2. Description of the Prior Art
Surgical trocars (or "trochars") generally employ a sharp pointed stylet needle for piercing a body part to be drained of fluid. The stylet needle is often inserted in a cannula through which the fluid can be aspirated after the stylet is removed or even while the stylet needle is still in place if it is loosely fitted in the cannula. This type of conventional trocar assembly of stylet and cannula is satisfactory for most macroscopic surgical purposes, but it presents a number of difficulties and disadvantages when it is required to remove microscopically small eggs or oocytes from a follicle or follicles in a human ovary, as is required in performing in vitro fertilization procedures. The principal disadvantage encountered with the prior trocars is that it is difficult or impossible to wash a follicle while under microscopic observation to insure that any oocyte present is removed. If the washing fluid is fed through the cannula to the drainage site in the ovary after the original follicular fluid has been aspirated, any oocyte which may have remained in the cannula may be washed back into the ovary and there lost. Furthermore, use of the prior trocars unduly prolongs the operative procedure where the pierced follicle must be washed several times, four for example; so that a patient must be kept under anesthesia a longer time than is desirable.